中文摘要：

采用固相烧结工艺制备了钙钛矿结构的（K0.5Na0.5）NbO3＋xwt%ZnO（x=0,0.5,1.0,2.0）无铅压电陶瓷。研究了ZnO掺杂对（K0.5Na0.5）NbO3陶瓷体系烧结行为和电学性能的影响。结果表明：ZnO掺杂能够有效地降低陶瓷烧结温度,抑制K和Na的挥发,提高陶瓷的致密性。当掺杂量为0.5 wt%、烧结温度为1115℃时,陶瓷的体积密度最大ρ=4.41 g/cm3。所有样品的晶粒形态均为层状堆垛结构,晶粒尺寸越大,层状堆垛形态越明显。晶粒形态和尺寸的变化与（K0.5Na0.5）NbO3陶瓷烧结过程中液相的形成和晶粒生长机制有关。适量的液相能够有效地提高陶瓷的致密性,获得均匀的微结构。当x=0.5、烧结温度为1115℃时,陶瓷具有最佳的电学性能：d33=118pC/N,kp=0.36,Pr=15.6μC/cm2。

英文摘要：

（K0.5Na0.5）NbO3＋xwt%ZnO（x=0,0.5,1.0,2.0） lead-free piezoelectric ceramics with perovskite structure were synthesized by solid state sintering.The effects of ZnO-doped on sintering behaviors and electrical properties were investigated.The experimental results show that ZnO-doped reduces effectively sintering temperature and restrains evaporation of K and Na ions to increase densification of the ceramics.The ceramics with x=0.5 sintered at 1115 ℃ show high density ρ=4.41 g/cm3.Grains with stacking of plates are observed in all ceramics,and the stacked plate morphology is more obvious with grain size increasing.These changes on morphology and size of grains are relative to liquid forming and crystal growth mechanism in sintering.The optimum volume of liquid phase can improve effectively the densification and obtain uniform microstructure.The ceramics with x=0.5 sintered at 1115 ℃ have optimal electrical properties d33=118 pC/N,kp=0.36 and Pr=15.6 μC/cm2,respectively.